Liquid filled compass



June 25, 1940. K. VOLKMANN LIQUID FILLED COMPASS 3 Sheets-Sheet 1 Filed Kay 24. 1938 INVENTOR.

ATTORNEY.

June 9 K. VOLKh dANN 3 4 LIQUID FILLED COMPASS Filed lay 24, 1938 I s Sheets-Sheet '2 l I Z5 l3 I 36 I I3 [I r 1 I l I Y 02 I I5 I5 I I 1 I 31 v June 25,. K. VOLKMANN LIQUID FILLED COMPASS 3 Sheets-Sheet 3 I Filed May 24, 1938 R o wm 1 m u N Patented June 25, 1940 2,295,548 LIQUID FILLED COMPASS I Kurt. Volkmann, Berlin-Oharlott'enburg,

assignor to Siemens .Apparate 'und nkter Maschinem Geseilschaft mit besohrl Haftung, Berlin, Germany, a corporation of Germany Application May 24, lssaseriai No. 209,333

' 3 Claims.

' This invention relates to direction 1 indicating I means and more particularly to a magnetic compass for vehicles.

One of the objects of the present invention is to provide. a novel compass, the basin of which is filled with a liquid, wherein the movement of the liquid-relative'to the compass is reduced to Another object of the invention is to provide a novel apparatus of the above character wherein the members. of a compass mounting are constructed to reduce the agitating efiect'upon a liquid contained therein.

A further object is to provide a novel liquid filled compass employing electrodes, wherein a vessel comprising a surface of revolution serves as a support for the electrodes, the vessel having an external supporting frame attached to an outer container. i

An additional-object is to provide novel damping means for an indicating element of a compass I Another object is to provide a novel compass,

the basin of which contains a liquid, wherein the movement of the liquid relative to the compass mounting is reduced to a minimum and wherein projecting vanes mounted upon a. direction indicating element'of 'said compass damp the movements of the element. 2

A further object is to provide novel means of the above character wherein the lag in the motion of the magnetic element due to agitation of' a surrounding liquid is reduced to a maximum,

An additional object to provide a novel elec- 85 trolytic compass wherein compensation is made for the expansion and contraction of 'the elec-' trolyte.

The above and further objects and novel features will more fully appear from the following 40 detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for purposes of. illustration only, and are not intended as a definition of the lim---' 45 its of the invention, reference for this latter purpose being had to the appended claims. In the drawings, wherein like reference characters refer to likeparts throughoutthe several s, 60 Fig. 1 is a side elevation, partly insection, of

one embodiment of the invention;

' Fig. 2 is a side elevation, partly in, section and with parts broken away, showing a second embodiment of the present invention;

a Fig.3 is a sectionpf the embodiment shown spective positions of the elements; and I ling element.

Germany May 29, 1937 (c ts-223) in Fig.1 taken along lin 3- with liartsibloken away;

Fig. 4 is a bottom view with ports broken, away of the embodimentshown in Fig. 1; I H Fig. 5 is a section of the embodiment shown in V' Fig. 1 taken along line 5-5 with parts broken; away;.. I Fig. 6 is a section of the embodiment ofFig. 2, taken along line 6-6, with parts. broken away;

Fig. 7 is a perspective view illustrating the re- 10 Fig.8 is a diagrammatic illustration of the application of the compass control to a control- The form of the invention illustrated in'the ll accompanying drawings, by way of example, is a magnetic compass mounted in a cylindrical. liquid-fllled transparent basin. The basin is proa vided with a removable cover portion having centrally disposed thereon, an expansible and 20 contractible corrugated metal vessel which is in communication with the basin and adapted td compensate for the changes in volume of. the liquid enclosed in said basin, said changes in volume being due to temperature variations. A U- 25 shaped frame portion is suspended from said cover to receive and hold a transparent cylindrlcal vessel having a smooth inner surface, -em-.

bedded in which are suitable electrodes for 00-- operation with electrodes mounted upon a mag-"' 30 netic compass float member which in turn is pivotally mounted by means of a vertical shaft on bearings in said cover and frame portion. A flange upon the periphery of said rose is calibrated for course readings whereby the compass may be read from the side of the above-men tioned transparent basin. Suitable vanes which, in the form shown, depend vertically from said float and extend into said-liquid are provided for damping the movements-of the float. 40

In the form shown in Fig. 1, a transparent container.or basin Ill of glass, for example, is provided having an annular lip Illa around the upper edge thereof. Upon lip "la is a ring packing ll upon which rests a cover portion I! for said basin.- Suitable means comprising a ring l3, engaging the outer edge of the cover l2, and a cooperating flange portion ll which engages lip Ilia, are

drawn together by screws ii, thereby compressing the packing H between said cover and basin and forming a liquid-tight joint.

Centrally disposed upon cover-l2 is a boss l6 in which-is a longitudinally adjustable screw I 1,

the inner end of which is conicaliy recessed to form a bearing for a compass shaft i8 .for'a ll purpose to be later explained. Adjacent said boss and angularly arranged at desired intervals are openings I! .which put the basin II in communication with a bellows or corrugated expansible and contractible metal vessel 2| attached to cover l2 by means of an annular flange member 2! which rests upon a raisedlipportion 22 upon said cover. vessel "2' is provided at the top thereof with a removable closure IQa through which the compass -may be filled with a suitable electrolyte for a. purpose to ap-- pear later. A

vIn ,order that a second bearing may be. properly held for said compass shaft, a U-shaped frame ,member 23 is provided having the upper extremities of the parallel arms thereof extending through cover i2 and held in a fixed. position by suitable nuts (not shown) engaging threads upon said extremities. A boss 24 centrally disposed at the lower portion of said frame member supports in a suitable threaded bore a bearing screw 25 similar to screw l|..

Frame 23 also serves to support a transparent which are mounted electrodes to be later described. The walls of vessel 26 comprisea surface of revolution and both the inner and outer surfaces of said vessel are free from projections which might entrain and agitate the liquid in 21 are provided with central bores 28 and 29, respectively, through which loosely extend the screws 25 and l'|.' The bores 28 and 29 also constltutepassages for the electrolyte. Since frame member- 23 is external to the vessel 2.

movements of the frame member will agitate only.

the electrolyte also external to said vessel.

In orderthat bubbles formed in the electrolyte in vessel, 26 may collect and easily escape through thebore 28 in the center of cover 21, said cover-isformed in the shape of a cone of low altitu'de'pthus constituting .the cover a gas mantle for the vessel.

The system 01' electrodesfor determining the position of the magnetic direction indicator as best shown in Figs. land '7 is constituted by 'an electrode 30 in the form of a ring imbedded in and flush with the inner surface of cover '21.

electrode is connected by a lead ill: to a semicircular control electrode 33 mounted upon the lower portion of shaft II and adapted for. ro- .tation therewith. The latter electrode, in turn, moves in rotation adjacent to and above a pair of opposed. electrodes and 35 which are imbedded in and flush with theinnen-surface o! the bottomof vessel 26. The electrodes 24 and 2| are connected by leads 3..., respectively, to sultable'external binding posts 38, 28 mounted upon the'outer cover i2, while electrode ll is connected to binding post an.

In operation of this embodiment, turning g movements the vehicle upon which the apparacylindrical vessel 26 upon the inner surface of.

; the compass basin. The vessel 26 and a cover aiiect the. movements of the float 32.

tus is mounted will cause the basin ll, frame 21, and vessel 26 to move therewithrelative to the magnetic indicator 2. The conformation of the inner surface of vessel 28 reduces the possibility of agitating the electrolyte therein whereby the liquid remains relatively quiet.. I

In Fig. 8 there are diagrammatically. ill trated the various electrical connections to the electrodes and the operation of the circuit upon relative movement. of the directional element, 10

whereby the movement. at the directional element is conveyed to a. remote controlling device. One side of a sourceot eleqtrical energy is connected to the binding post "a. which post is electrically connected to the stationary electrode ll. Elec- 15 trode ill is mounted on. the top cover 2'! and is at all times directly above the cooperating movable electrode 3| mounted on directional element 32. The electrolyte between electrodes II and it conveys the electrical energy between these m electrodesand this energy is further conveyed by the conductor Ila (see Fig. '7) to the semicircular electrode 32 mounted on the directional element 32 and cooperating with electrodes 34 and 35, Electrical energy is conveyed between as electrodes 33 and the cooperating electrodes ll and I5 by-means of the electrolyte therebetween,

the amount of energy conveyed to the respective electrodes and 15 being determined by the relative position of the control electrode" with 30 respect to electrodes 3 and 15, respectively. Since the positionv of'electrode 33 is determined by that of the directional element, the, electrical energy is conveyed to the binding post 38 and 39 I and from these to the windings of a conventional 86 rotary magnet .whose'armature controls a servomotor in the manner well known in the art whereby a contr'ol surface of the craft may be actuated in response to relative deviation of the craft and the directional element.

The liquidin the above-described vessel 26 will remain relatively. quiet and will not appreciably In order to damp any movements of the float, there are provided, in the second embodiment shown in a Fig. 2, a series of vanes ll which depend-ver-" tically from the float. Withthe exception of vanes 40, the second embodiment is similar to the first embodiment. These damping bodies or vanes are constituted by narrow stream-lined 0.

strips which are preferably disposed transversely to their path of movement, 1. e., such that the wide -face of the strip will be presented to the liquid if the fiti'at should move in azimuth. The vanes aresymmetrically arranged upon diam eters oi the float and do not extend beyond the outer circumference thereof.

The operation of the second embodimentis similar to that of the first with the addition that any angular.motion which may be imparted to the host 32 by said turning movements will be immediately damped by the vanes ll .acting up-' on the electrolyte.

' There is, thus provided a novel mounting for a compass employing liquid within the basinthere- 06 of. The device provides means for mounting suitable electrodesand'a compass float which means are so constructed and arrang that the liquid in which they are immersed is tated as little as possible due'to' movements of said means. 10

Means are also provided which immediately damp any movements of the compass float relative to the liquid. Thus, inaccuracies in compass readings due to an agitated electrolyte or liquid are reducedto a minimum. a

' insulated electrodes mounted on said vessel and.

the electrode housing. However, this frame. member may be of any suitable shape.

Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention, as the same will now be understoodby those skilled in the art. For a definition of the limits of the invention, reference will be had primarily to the appended claims. v

What is claimed is: v

1; In a compass having a basin containing an electrolyte, a, vessel including a surface of revolution within said basin, a direction indicating element pivoted within said vessel for rotation about a vertical axis passing centrally through said basin, 8; pair of adjacent circular electrodes. respectively mounted upon said vessel and said element and the peripheries of said electrodes positioned equally distant about said axis, a second electrode mounted on said element, a pair of positioned in a horizontal plane. parallel and adjacent to the plane of said second electrode, and means for electrically connecting the electrodes on said element whereby the current fiowing.-t said pair of insulated electrodes is a function of the angular relation of said vessel and said element.

-2. In a compass having a basin containing an electrolyte, a vessel including a surface of revolution within said basin, a direction indicating element pivoted within said vessel for rotation about a vertical axis passing centrally through said basin, a circular electrode mounted upon said vessel, a second circular electrode mounted upon said element adjacent said first-named circular electrode, the peripheries of said first-named and said-second circular electrodes positioned equally distant about said axis, means for supplying electrical energy to said first-named circular electrode, a secondelectrode positioned on said element and'disposed concentrically with respect to said axis, a pair of insulated electrodesmounted upon said vessel in a horizontal plane with respect to said axis and positioned parallel and adjacent to the plane of .said second electrode, and means for electrically connecting the electrodes on said element whereby the current flowing to said pair of insulated electrodes is a containing an electrolyte, a transparent vessel constructed to form a surface of revolution within said basin, means allowing liquid communication between said basin and said vessel, 9. direction indicating element pivoted within said vessel for rotation about a vertical axis passing centrally through said basin, a circular electrode mounted in the upper wall of said vessel, a second circular electrode mounted upon said element adjacent said first-named circular electrode, the peripheries of said first-named and said second circular electrodes positioned equally distant about said axis, a pair of insulated electrodes mounted in the lowerwall of said vessel, a second electrode mounted on said element and disposed concentrically with respect to said axis in a horizontal plane parallel and adjacent to the plane of said insulated electrodes, and means for electrically connecting the electrodes on said element whereby the current flowing to said pair of insulated electrodes is a function of the angular relation of said vessel and said element.

KURT VOLKMANN. 

